/Engine/Source/Runtime/Sockets/Public/SocketSubsystem.h
Typically, it is better to use GetLocalBindAddresses as it better supports hybrid network functionality and less chances for connections to fail due to mismatched protocols.
virtual [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [FInternetAddr](API\Runtime\Sockets\FInternetAddr) > GetLocalBindAddr ( [FOutputDevice](API\Runtime\Core\Misc\FOutputDevice) & Out )